Low Speed Wind Tunnel Support System Wdpss-8 Cable System For Static Experiment

Static experiments as well as dynamic experiments of the scale model of theaircraft in low-speed wind tunnels by using a wire-driven parallel suspension system,WDPSS-8, can make a meaningful breakthrough for the aviation industry. Based onthe development of robotics and experimental techniques, a number of theoreticalresearch outcomes have been achieved. Due to the softness of wires, the complexfluid-structure interaction behavior between wires and air must be considered. Withthe improved performance of personal computer hardware, the three-dimensionalsimulation of fluid-structure interaction behavior becomes more and more popular indomestic and in foreign countries.Using single interaction function of ANSYS Multiphysics and both single andtwo-way fluid-structure interaction functions of ANSYS WORKBENCH platform,the fluid-structure interaction phenomena of wires of WDPSS-8which has beenimplemented by experiments of static derivatives in0.9m×1.1m low speed windtunnel are analyzed. And then the vortex induced vibration of WDPSS-8is initiallystudied based on CFX. Through a series of simulation comparison, fluid-structureinteraction of wires can reflect more really based on ANSYS. Therefore, once againthe static three-dimensional CFD simulation of wires in WDPSS-8of4m×3m bigwind tunnel are given using this method, also the real posture of the scale model ofthe aircraft will be obtained by solving the problem of direct posture kinematicsaccording to the values of the lengths of wires after the simulation, the error betweenwhich and the desired posture will provide the real-time feedback compensatoryvalues for the motion control of the scale model of the craft.The simulation results of two kinds of different flow field have shown that elementSolid186is fit as the element of wires in analysis of fluid-structure interaction; wireswith a diameter of4mm in a wind tunnel of35m/s have a certain degree ofdeformation, including the bending to wind behavior, lateral vibration behavior andaxial tensile behavior along the wire and the behavior of bending to wind plays a dominant role in the deformation of wires.To be specific, the fluid results of0.9m×1.1m wind show that wires benddownwind, which consist with those from experiments of static derivatives. As isshown in simulation by using ANSYS Multiphysics, the pre-tension of wires canimprove the behavior of the fluid-structure interaction of wires, and the phenomenoncan be cut down by optimizing the wire tension. By using the post-processingfunction of CFX module the lift coefficient curve of wires is obtained. It is found thatthe lateral vibration behavior of wires is greatly related with the wind direction, thewire inclination angle and the wind speed, which will provide a theoretical basis foranalyzing the influence factors of the vortex-induced vibration behavior. The fluidresults of4m×3m wind tunnel show that behind the wires negative pressure areaexits, which means vortex shedding phenomenon happens. And the pressure beforeand after the wires vary over time and the pressure difference tend to constant valuebecause of the elastic damping effect of wires. The solid results show that The resultsof direct posture kinematics analysis show that changes of the length of wires willmainly make the aircraft moves along the wind and deviates from the predeterminedtrajectory slightly.